How to remove image title when hovering over image

I would like to remove the image title when hovering over an image. I used a fix from this thread:

http://wordpress.org/support/topic/how-to-remove-image-title-when-hovering-over-image?replies=38

…but it removes the title all together. When I click on the picture, I would still like to see the title in my lightbox.

Any ideas?